Researchers have known for a long time that regular aerobic exercises like walking, jogging or cycling help to lower high blood pressure and also help to prevent strokes and heart attacks (Arq Bras Cardiol, 2016 May; 106(5): 422–433). However, there is data to show that a person can suffer a stroke or heart attack while lifting heavy weights because during heavy lifting, high blood pressure rises even higher. Many doctors recommend resistance exercises to help treat high blood pressure, but people with high blood pressure need to be very careful if they try to lift heavy weights. Instead, they should lift lighter weights with more repetitions and stop doing a lift if they feel pain.
A review of 14 studies of 253 people with high blood pressure, average age 60, found that lifting weights for eight weeks or longer lowered high blood pressure by the twentieth training session, and the blood pressure stayed lower for 14 weeks after the people stopped lifting weights (Scientific Reports, January 2023;13(1):201). Eight to ten weeks of strength training led to a reduction of 10 mmHg in systolic pressure and 4.8 mmHg in diastolic pressure, and was more effective in lowering high blood pressure in men younger than 50 compared to those older than 50. Strength training was most effective in lowering high blood pressure when people lifted more than 60 percent of the maximum weight that they could lift (one rep max), and they lifted at least twice a week for at least eight weeks.
High Blood Pressure is Common
High blood pressure is associated with smoking, drinking alcohol, obesity, an unhealthy diet, and a sedentary lifestyle. According to the Centers for Disease Control and Prevention (CDC), more than 116 million North American adults have high blood pressure, and fewer than 24 percent are able to get their blood pressures to a safer level below 140/90. Furthermore, 19 percent of adults have hypertension that cannot be brought to normal with any combination of medications (Hypertension, 2019;73(2):424–431).
How Can Lifting Weights Help to Lower Blood Pressure?
Exercising temporarily increases blood pressure and heart rate, widens blood vessels and increases blood flow. It increases blood flow by significantly widening blood vessels by relaxing the autonomic nervous system (Circ Res, 2017, Jan 20; 120(2): 249–251) and increasing production of nitric oxide that widens blood vessels. Nitric oxide remains elevated after exercising, and blood pressure is usually lower for a while after you finish exercising. This applies to both aerobic and resistance exercises. Any exercise strengthens heart muscles and blood vessels, so blood vessels can remain relaxed to continue at a lowered blood pressure (Curr Hypertens Rep, 2015;17(10):77)
Colon Bacteria May Regulate High Blood Pressure
Several recent articles show that exercise might help to prevent heart attacks and lower high blood pressure by changing the bacteria in your colon. One study found that people with high blood pressure are at high likelihood to have Bacteroides2 (a specific bacteria in their colons associated with eating meat) and reduced amounts of bacteria that are associated with eating a plant-based diet (Front Microbiomes, May 26, 2023;2:). When hypertensive people change to an anti-inflammatory plant-based diet that restricts meat, their blood pressures were reduced significantly, as were the number of colon bacteria associated with eating meat, and the colon bacteria associated with eating plant-based foods increased.
Mice that have high blood pressure also have a marked reduction in the diversity of different types of colon bacteria and a marked increase in the types of colon bacteria associated with high blood pressure. When the researchers transplanted stool from people with high blood pressure into germ-free mice, the mice developed high blood pressure. In another study, researchers transplanted feces from mice with normal blood pressure into mice with high blood pressure and the mice with high blood pressure had their pressures return to normal (Front Physiol, March 8, 2019;10).
Exercise Increases Short Chain Fatty Acids that Lower Blood Pressure
It is agreed by most of these researchers that a plant-based diet helps to lower high blood pressure because all plants contain soluble fiber that cannot be absorbed in the upper intestinal tract. When soluble fiber reaches the colon, bacteria there convert it into short chain fatty acids (SCFAs) that are absorbed into the bloodstream and help lower high blood pressure (Curr Hypertens Rep, 2017 Apr19(4): 25), high cholesterol (J Agric Food Chem, 2017 Dec 20;65(50):10984-10992) and inflammation (Curr Hypertens Rep, April 2017;19(4):25). People who have high blood pressure have lower colon levels of bacteria that make SCFAs (Front Cell Infect Microbiol, 24 August 2017;7). The exciting news is that exercise increases the number of colon bacteria that make short chain fatty acids (Oxid Med Cell Longev, 2017: 3831972).
If you have high blood pressure, you should check with your doctor about lowering high blood pressure by exercising, losing excess weight and eating a plant-based diet that severely restricts mammal and processed meats. Check with your doctor to see if there is any reason why you should not lift weights. For strength training routines to help you lower high blood pressure, see Resistance Exercise You Can Do at Home